The Buffalo Bills have a clear vision for what they want in their offensive linemen.

Size.

Lots of it.

The Bills added some serious road graders up front during the draft earlier this month, spending three of their seven picks on linemen – all of whom are at least 6-foot-5 and 310 pounds. The Bills currently have 15 offensive linemen on their roster, at an average height of 6-5 and average weight of 325 pounds.

According to research conducted this week by ESPN’s Mike Rodak, that gives the Bills the biggest offensive line in the NFL – by almost 5 pounds. The Oakland Raiders are next, at an average of 320 pounds.

“We’re going to keep going big,” Bills Director of Player Personnel Jim Monos said during the draft.

The Bills’ projected starters along the line, from left to right – Cordy Glenn, Chris Williams, Eric Wood, Kraig Urbik and Cyrus Kouandjio – average 6-5 and 323 pounds.

Bills coach Doug Marrone said the effort to get bigger boils down to matchups.

“I think you can see it throughout the AFC East,” he said. “You look at the defensive linemen that are in this division, and you’re going against everyone in New York, to the guys in Miami and obviously the players in New England. ... The players inside, everyone is getting bigger.”

The Bills for years have struggled to block Patriots nose tackle Vince Wilfork, a 6-2, 325-pound bowling ball in the middle of the defensive line. New England also added defensive tackle Dominique Easley (6-2, 288) in the first round of the draft this month.

The Jets have a pair of terrors on the interior of their defensive line in Muhammad Wilkerson (6-4, 315) and Sheldon Richardson (6-3, 294), while the Dolphins also have a couple of 300-pounders in Jared Odrick and Randy Starks.

“Obviously they brought me, Cyril and Cyrus in, so that shows you a lot of what they want, plus the guys they already have. Everybody on the line is real athletic, real strong and powerful – can move anybody on the defensive line.”

The trade for Mike Williams and moving up in the draft to acquire Sammy Watkins have been highly publicized ways in which the team has gone about providing more support for second-year quarterback EJ Manuel, but the offensive line projects to have at least two new starters in Williams and Kouandjio, as well.

“We wanted to improve the offense, and we think outside we brought some weapons in, but we also needed to solidify the line,” General Manager Doug Whaley said during the draft.

While the Bills finished the 2013 season second in total rushing yards, the team’s average of 4.2 yards per carry was tied for 14th in the NFL. The upgrades to the line should help in that regard.

“We runnin’ that rock, I can tell you that,” Kouandjio said.

Bills quarterbacks were sacked 48 times in 2013 – tied for fourth most in the NFL – and hit 108 times, alone as the fourth most in the league.

“We have to do a good job in developing the players that we have and hopefully create some competition there,” Marrone said of the offensive line at the end of the season.